海南椰子木维管束形态特征及其与物理力学性能的关系OA北大核心CSTPCD

The vascular bundle is an important component whose microscopic characteristics and distribution affect coconut wood's physical and mechanical properties.In order to evaluate the variation of vascular bundles and their effect on the physical and mechanical properties at various tree positions,40-year-old coconut wood from Hainan province of China was tested.The distribution density,diameter,cross-section area,and total area percentage of vascular bundles were evaluated in height and radial directions,while the total area percentage of vascular bundle effect on density and mechanical properties were also investigated.The results showed that there are no significant differences in the morphological characteristics of vascular bundles and physical and mechanical performance among different trees,except in total area proportion of vascular bundles and MOR.In the radial direction,the distribution density,diameter,cross-section area,and total area percentage of vascular bundles gradually increase from the center to the periphery,showing a significant positive linear correlation along the radial position.The density and mechanical properties of coconut wood gradually increase from the center to the periphery,with a high positive linear correlation with the total area proportion of the vascular bundles.In the height direction(from bottom to top),the diameter and cross-section area of the vascular bundles gradually decreased,and the distribution density and total area percentage of the vascular bundles first increased and then decreased,with an overall strong negative linear correlation.In general,the density and mechanical properties of coconut wood increase as the area percentage of vascular bundles increase.A model of the physical and mechanical properties of coconut wood is developed based on the proportion index of vascular bundle area.The predicted results from the model provide a basis for sawing and grading coconut wood.